Glycoprotein nonmetastatic B as a prognostic indicator in small cell lung cancer

Glycoprotein nonmetastatic melanoma B ( GPNMB ) is a type I transmembrane glycoprotein which is overexpressed in many tumors and seems to play a critical role in metastasis of malignant tumors. The purpose of this study was to determine GPNMB expression in small cell lung cancer ( SCLC ) and analyze the prognostic value in patients with SCLC . A total of 132 cases of SCLC s were analyzed immunohistochemically on tissue microarrays ( TMA s). Patients were divided into weak‐positive and strong‐positive GPNMB groups. In addition, serum GPNMB was evaluated by enzyme‐linked immunosorbent assay ( ELISA ). The average serum GPNMB concentration was 1054.15 ± 363.71 pg/mL in the weak‐positive group, 2611.52 ± 457.57 pg/mL in the strong‐positive group, and 427.61 ± 273.9 pg/mL in the control. The strong‐positive group showed significantly higher serum GPNMB levels than the weak‐positive group and healthy control (p < 0.01). Overall survival in the weak‐positive GPNMB group was significantly longer than in the strong‐positive group (27 months vs 15 months, p < 0.01). These results suggest that the expression of GPNMB may be useful as a prognostic indicator in patients with SCLC .